高中英語語法全解-情態(tài)動詞

1、第四章 情態(tài)動詞（一） 情態(tài)動詞表示說話人對動作或狀態(tài)的各種觀點(diǎn)和態(tài)度，如需要、猜測、意愿或懷疑等。情態(tài)動詞有詞義，但不完全，是所謂的“輔助性”動詞，在句中不能單獨(dú)充當(dāng)謂語。一、 情態(tài)動詞的特征和形式A. 情態(tài)動詞的各種形式見下表：情態(tài)動詞 may mightcan could must have to ought to will would shall should need dare used to否定式 may not might not cannotcan not could not must not do not have to ought not to will not would

2、 not shall not should not need not dare not used not to did not use to簡略否定式 mayn't（老式英語，現(xiàn)在不常見） mightn't can't couldn't mustn't don't have to oughtn't to （否定句中to可省略） won't wouldn't shan't （只用于英國英語） shouldn't needn't daren't usedn't to didn't

3、 use toB情態(tài)動詞除ought to, used to等外，后面只接不帶to的不定式。 1情態(tài)動詞+do You shouldn't be so careless. 你不該這樣粗心大意。 Jessica told him yesterday she might not go on the trip. 杰西卡昨天告訴他，她可能不去旅行了。 Difficulties can and must be overcome. 困難能夠而且必須克服。 2情態(tài)動詞+be doing She must be listening to pop music. 她肯定在聽流行音樂。 You should

4、 be reviewing your lessons. 你應(yīng)該在復(fù)習(xí)功課。 My mother maymight be cooking now. 我媽媽可能正在做飯。 3情態(tài)動詞+have done They might have visited the Great Wall. 他們可能參觀過長城了。 He must have got up very early to catch the train. 他一定起得很早去趕火車了。 You ought to have come earlier. 你本該早一點(diǎn)兒來。 4情態(tài)動詞+be done This word can also be used

5、as a verb. 這個(gè)詞也可以用作動詞。 Something must be done to stop pollution. 必須采取措施來制止污染。 The work ought to have been finished long ago. 這工作早就該完成了。 C. 情態(tài)動詞第三人稱單數(shù)一般現(xiàn)在時(shí)沒有詞形變化。 You ought to wear a raincoat. 你應(yīng)該穿件雨衣。 She ought to wear a raincoat. 她應(yīng)該穿件雨衣。 Plants must have oxygen in order to live. 為了存活植物必須有氧氣。 A pla

6、nt must have oxygen in order to live. 為了存活植物必須有氧氣。D. 情態(tài)動詞的時(shí)態(tài)并不是區(qū)分時(shí)間的主要標(biāo)志。在一些場合中，情態(tài)動詞的現(xiàn)在式和過去式都可以表示現(xiàn)在時(shí)間、過去時(shí)間或?qū)頃r(shí)間。 I'm afraid it might rain tonight. 我看今晚可能要下雨。 Could I borrow your thermos 我可以借用你的暖水瓶嗎？ It's a nice day today. We could go for a walk. 今天天氣不錯，我們可以出去散散步。 E. 情態(tài)動詞是互相排斥的，一般不允許兩個(gè)意義相近的情態(tài)

7、動詞連用?！菊`】Soldiers must have to obey orders. 【正】Soldiers have to obey orders. 軍人必須服從命令。【正】Soldiers must obey orders. 軍人必須服從命令。【誤】Can I be able to borrow two books at a time【正】Can I borrow two books at a time 我能一次借兩本書嗎？【正】Will I be able to borrow two books at a time 我能一次借兩本書嗎？二、 情態(tài)動詞的意義和用法A. may和might

8、1表示請求、許可，常譯為“可以”。 在口語中可用can, could代替may，但在正式場合用may。表示允許時(shí)，也可用might代替，might不表示過去時(shí)，而是表示口氣比較婉轉(zhuǎn)。 You may take this seat if you like. 如果你喜歡可以坐這個(gè)位置。 MayCan Could Might I have a talk with you 我可以和你談?wù)剢幔?- MayMight I come into the room to see my mother 我可以進(jìn)房間看我母親嗎？ - No, you mustn't. She needs to have a g

9、ood rest. 不，你不能進(jìn)。她需要好好休息。提示：May I . 問句常見的肯定回答和否定回答。肯定回答Yes, please.Certainly.Yes, of course.Sure.Go ahead, please. 否定回答No, you can't. （最常見）No, you mustn't. （具有強(qiáng)烈禁止的意思）Please don't. You'd better not.I don't think you can.I'm sorry it's not allowed. 2表示推測，可譯為“可能，也許”。 Your m

10、ath teacher maymight be in his office. 你們的數(shù)學(xué)老師可能在辦公室里。（一般情況下，might表示的可能性很小） The light isn't on. It maymight be broken. 那盞燈沒有亮，它可能壞了。 There may might be some ink left in the bottle. 瓶子里也許還剩點(diǎn)兒墨水。 注意： 用may表示推測一般不用于疑問句，在疑問句中通常用can來代替。 Can he be at home 他可能在家嗎？ - Can it be true 這可能是真的嗎？ - It may be,

11、or may not be. 可能是，也可能不是。 3用在目的狀語從句中，構(gòu)成謂語。 He wants to take a taxi so that he may get there in time. 他想坐出租車，這樣他就能及時(shí)到達(dá)那里。 I arrived at the airport earlier in order that I might meet him. 我早早地就到了機(jī)場為了能接到他。 4 有時(shí)可以用于祈使句表示祝愿。 May you succeed. 祝你成功 May you be happy. 祝你快樂。 May that day come soon. 希望這一天早日到來。

12、 B. can和could 1 表示能力，可譯為“能，會”。 I can swim. 我會游泳。 Emily can dance well and her mother could dance well when she was young. 艾米麗舞跳得很好，她媽媽年輕時(shí)舞跳得也很好。 The cinema can seat 1,000 people. 這電影院能容納1，000人。 I could not read such an easy book when I was 7 years old. 我七歲時(shí)連如此簡單的書我也看不懂。 2 表示允許、許可，常用在口語中。could比can語氣上

13、要客氣。 - Could I use your dictionary 我可以用一下你的字典嗎？ -Yes, go ahead. 可以，用吧。（或Yes, you can. 但不能說Yes, you could.） Could Can you tell me how to get to the zoo 勞駕，你能告訴我怎么去動物園嗎？ He asked me whether he could take the book out of the reading room. 他問我可不可以把書帶出閱覽室。 3表示推測，可用于肯定句（can罕見）、否定句和疑問句，但更常見于疑問句或否定句。在此種用法中c

14、an和could沒有時(shí)態(tài)的區(qū)別，只是表示可能性的大小，can表示推測的可能性比could大。 Can he be ill at home 他會是生病在家嗎？ Can the story be true 這個(gè)故事會是真的嗎？ He cannot be at home. 他不可能在家。 You mustn't smoke while you are walking around in the woods. You could start a fire. 在林子里走時(shí)一定不要吸煙，那樣可能會引起火災(zāi)。 4表示驚異、懷疑、不相信等態(tài)度，主要用于否定句和疑問句中。 How can you be

15、so careless 你怎么這么粗心？ Where can could they have gone 他們會去了哪里？ He can'tcouldn't be over sixty. 他不可能超過60歲。 5Could可以用在虛擬條件句中。 If I could fly, I should be very happy. 如果我能飛， 我會很高興。 If you had followed my advice, you could have finished it. 如果你當(dāng)時(shí)聽我的，你早就做完了。 If you had tried harder, you could have

16、passed your exam. 如果你再努力些，你就能通過考試了。 can與be able to的區(qū)別 can表示“能力”時(shí)，和be able to相當(dāng)，許多場合都可以互相替換。但當(dāng)敘述過去經(jīng)過一番努力才能完成的事情或前面有特殊說明，表示你有能力時(shí)，只能用be able to?！菊緾an you speak any foreign languages 你會說外語嗎？【正】Are you able to speak any foreign languages 你會說外語嗎？【誤】The fire spread the building quickly but everybody could

17、 escape. 【正】The fire spread the building quickly but everybody was able to escape. 大火迅速蔓延到整幢大樓，但大家都逃了出來。【正】The fire spread the building quickly but everybody managed to escape. 大火迅速蔓延到整幢大樓，但大家都想法逃了出來。 be able to 比can有更多形式。 No one could answer the question. 沒人能回答這個(gè)問題。（這里could可用was able to 代替） When he

18、 grows up, he will be able to support his family. 他長大后就能養(yǎng)家了。 Frank is ill. He hasn't been able to go to school for one week. 弗蘭克病了，已經(jīng)一周沒去上學(xué)了。 I'm sorry for not being able to help you in time. 對不起，不能及時(shí)幫你的忙。 could經(jīng)常和動詞see, hear, smell, taste, feel, remember, understand等連用。 When we went into th

19、e house, we could smell something burning. 當(dāng)我們走進(jìn)屋子時(shí)，我們聞到什么東西燒焦了。（不用was able to） She spoke in a very low voice, but I could understand what she said. 雖然她講話的聲音很低，但我還是明白了她說的話。 在談?wù)撜f話時(shí)發(fā)生的動作，用can，不用be able to。 【誤】Look! I'm able to swim. 【正】Look! I can swim. 看，我會游泳了！Cmust和have to 1must表示有做某一動作的必要或義務(wù)，強(qiáng)調(diào)

20、主觀看法，可譯為“必須，應(yīng)該”。 Everyone must obey the rule. 人人都必須遵守制度。 We must do everything step by step. 我們必須逐步做每件事。 Teachers must be patient enough with their students. 老師必須對學(xué)生有足夠的耐心。 2have to 表示因客觀需要促使主語不得不做某事。 You can't turn right here. You have to turn left. 你不能在這里右拐，你必須左拐。 My eyesight is very poor. I h

21、ave to wear glasses for reading. 我的視力很差，看書時(shí)不得不戴眼鏡。 You have to pass a test before you can get a driving licence. 你在取得駕照之前必須先通過考試。 提示： 在口語中，我們可以使用have got to來代替have to. I've got to work on Sunday. 我不得不星期天工作。 When has Ann got to go 安必須什么時(shí)候走？ 3must 與have to的比較。 must 與have to在表示“必須”這個(gè)意思時(shí)意義相近，但在用法上有所

22、區(qū)別。 must含有說話者的強(qiáng)烈決意（表示主觀的看法），have to 則表示外力環(huán)境或習(xí)慣使然（即表示客觀的必要，作“不得不”解）。 I must study hard. 我必須努力學(xué)習(xí)。（發(fā)自內(nèi)心的決定） I have to study hard. 我不得不努力學(xué)習(xí)。（外界因素逼迫） You must stay for supper. 你必須留下來吃晚飯。（because I want you to） You have to stay for supper. 你得留下來吃晚飯。（because there is nowhere else to go） must只有一種形式，而have to

23、可有多種時(shí)態(tài)。 They had to put off the sports meet due to the bad weather. 由于壞天氣，他們不得不推遲運(yùn)動會。 These last two days he has had to take a rest at home. 這兩天他必須一直在家休息。 must的否定式和have to的否定式的意思完全不同。 You must keep it a secret. You mustn't tell anyone. 你必須保密，你不可以告訴任何人。（mustn't表示“禁止”） You don't have to te

24、ll me the secret. 你不必告訴我這個(gè)秘密。（don't have to意思是“沒有必要”= don't need to） 4must用于表示推測，它的肯定程度比may, might, could大得多，一般只用于肯定句。 must do (這里的do通常是狀態(tài)動詞或系動詞) ，表示對現(xiàn)在狀態(tài)的推測。 He must be very lazy for his desk is very untidy. 他肯定很懶，因?yàn)樗恼n桌很不整潔。 Carol must get very bored with her job. She does the same thing e

25、very day. 卡羅爾肯定對她的工作厭煩了，她每天都做同樣的事。 must be doing表示對現(xiàn)在動作或狀態(tài)的推測。 Put on more clothes. You must be feeling cold with only a shirt on. 多穿點(diǎn)兒衣服，你只穿一件襯衣，肯定覺得冷。 must have done表示對過去的動作或狀態(tài)的推測。 The ground is wet. It must have rained last night. 地面是濕的，昨晚肯定下雨了。 I didn't hear the phone. I must have been aslee

26、p. 我沒聽見電話鈴響，我一定是睡著了。 提示： must表示推測只用于肯定句，否定句和疑問句要用can, could來代替must。 He's just had his lunch. He can't be hungry already. 他剛吃過午飯，不會餓的。 They have just arrived here. They can't know many people. 他們剛到這里，不可能認(rèn)識很多人。 Leslie walked past me without speaking. He can'tcouldn't have seen me.

27、萊斯利從我身邊走過而沒打招呼，他肯定沒看見我。 5must可用來表示根據(jù)邏輯推理必然要發(fā)生的事，可譯為“必然會，總是會”。 We all must die. 我們都會死。 Truth must be out. 真相必然會大白的。 Winter must be followed by spring. 冬天到了，春天還會遠(yuǎn)嗎？ 6must有時(shí)可用來表示“偏偏”的意思。 Why must it rain today 為什么偏偏在今天下雨？ When I was taking a nap, a student must knock at the door. 正當(dāng)我午睡時(shí)，偏偏一個(gè)學(xué)生在這個(gè)時(shí)候來敲門。

28、 D will和would 1.will和would可用于第二人稱疑問句，表示請求和建議等。would比 will委婉客氣。 Will you have some tea 你喝點(diǎn)茶，好嗎？ Will you share your happiness with us 你可以把你的歡樂與我們共享嗎？ Would you pass this book to the student in the last row 請你把這本書傳給最后一排的學(xué)生好嗎？ 必背： WillWould you . 表示請求和建議的答復(fù)。 肯定回答 Yes, please. 是的，請。 Certainly. 當(dāng)然可以。 Sur

29、e. 當(dāng)然了。 All right. 好??！ 否定回答 I'm sorry. I can't. 對不起，不行。 No, thank you. 不，不行。 No, I won't. 不，不行。 2will和would可表示意志、愿望和決心，用于各種人稱陳述句。 I will do anything for you. 我愿為你做任何事。 I will never tell you the secret. 我永遠(yuǎn)不會告訴你這個(gè)秘密。 None is so blind as those who won't see. 不愿看的人眼睛最瞎。 They would not l

30、et him in because he was poorly dressed. 他們不讓他進(jìn)去因?yàn)樗轮婆f。 3will和would可表示某種傾向或習(xí)慣性動作。will表示現(xiàn)在的習(xí)慣動作，would表示過去的習(xí)慣動作。 He will surf the Internet every night. 他每天晚上都在上網(wǎng)。 The boy will sit there hour after hour looking at the traffic go by. 那男孩常常坐在那兒好幾個(gè)鐘頭，看著車輛行人通過。 He would be nervous when he met strangers. 遇

31、見陌生人時(shí)他總是很緊張。 In class he would ask some silly questions, and his classmates would laugh at him. 課上，他總是問一些蠢問題，他的同學(xué)們總是嘲笑他。 4will可表示固執(zhí)堅(jiān)持，這時(shí)will不可使用'll的簡略形式。用于非人稱主語時(shí)，表示物體的固有性質(zhì)和傾向。 I will take the job, and no one can stop me. 我就要這個(gè)工作，沒有人可阻止我。 He won't do what he's told. 他就是不愿按所吩咐的去做。 The wind

32、ow won't open. 窗子打不開。 This glass will not crack under heavy pressure. 這種玻璃在重壓下也不會破碎。 5will表示將來時(shí)間時(shí)，不可用于條件狀語從句，但will表示意愿或決心時(shí)，可用于條件狀語從句。 If you will read the book, I'll lend it to you. 如果你愿意讀這本書，我會把它借給你。 If you will give up smoking, your health will improve. 如果你愿意把煙戒掉的話，你的健康狀況就會好轉(zhuǎn)。 6will和would可

33、表示推論或猜測。 The patient took the sleeping pills an hour ago. He will be asleep now. 病人一小時(shí)前吃的安眠藥，現(xiàn)在應(yīng)該睡著了。 It would be about ten when he left home. 他大約在十點(diǎn)鐘離開的家。 I thought he would have told you about it. 我認(rèn)為他已告知你此事。 It would be raining when she went home. 她回家時(shí)可能正在下雨。比較： Would you like .表示邀請 Do you like .

34、表示習(xí)慣 Do you like going go the cinema 你喜歡看電影嗎？ Yes,I go to the cinema a lot. 是的，我經(jīng)常去看電影。 Would you like to go to the cinema tonight 今天晚上去看電影好嗎？ Yes,I'd love to. 非常樂意。 Eshall和should 1shall 表示征詢意見或請求指示，用于一、三人稱疑問句。 Shall I carry it for you 我來幫你搬它，好嗎？ Shall we sing a song 我們唱一支歌，好嗎？ Shall they wait o

35、utside 讓他們在外面等嗎？ Shall the waiter bring meals to your room 要服務(wù)員把飯送到你房間去嗎？提示： Shall I open the window 我打開窗子好嗎？ Will you open the window 你打開窗子好嗎？ Shall he open the window 他打開窗子好嗎？ 表示說話人的意愿，有“命令、允諾、警告、決心”等意思，用于第二、三人稱陳述句中。 You shall do as I say. 按我說的做。（命令） He shall be sorry for it one day, I tell you. 我

36、告訴你，總有一天他會后悔的。（警告） You shall fall behind in your exam if you keep playing. 如果你一直玩，你就會在考試中落后。 Nothing shall stop us from carrying out the plan. 什么也阻止不了我們執(zhí)行這項(xiàng)計(jì)劃。（決心） He shall have the book when I finish reading. 我看完這本書就給他看。（允諾） I shall do my homework after reading this story book. 讀完這本故事書后我就做作業(yè)。 2shou

37、ld 表示義務(wù)，意為“應(yīng)該”（某件事宜于做），用于各種人稱。 Children should obey their parents. 兒童應(yīng)該服從他們的父母。 One shouldn't be selfish. 人千萬別自私。 Customers who get bad service should complain, shouldn't they 沒有得到滿意服務(wù)的顧客應(yīng)該抱怨，不是嗎？ 常與what, how, why等詞連用，表示意外、驚訝等情緒。 How should I know 我怎么會知道呢 Why should I fear 我為什么會害怕？ What shou

38、ld she do but cry for help 除了呼救外，她還能干什么？ I don't know why you should think I did it. 我真不知道你憑什么認(rèn)為這件事是我干的。 表示對過去、現(xiàn)在或?qū)砬闆r的某種推測，可譯為“可能、照說應(yīng)該”。 It should be fine tomorrow. 明天可能天是晴天。 He should be taking a bath now. 他可能在洗澡。 It's nearly seven o'clock. Jack should be here at any moment. 已經(jīng)快七點(diǎn)了，杰克隨

39、時(shí)都可能到這兒。 The film should be very good as it is starring first-class actors. 這部新電影是一流演員主演的，估計(jì)拍得很好。 表示對現(xiàn)在或以前的動作的責(zé)怪、批評（應(yīng)做的事卻沒做）。 The boys shouldn't be playing football. They should be at school. 這些男孩子不應(yīng)該在踢足球，他們應(yīng)該在上課。 You shouldn't have entered the teachers' office without permission. 沒有允許你們

40、不應(yīng)該進(jìn)老師辦公室。 Fought to 1表示義務(wù)，意為“應(yīng)該”（因責(zé)任、義務(wù)而該做），口氣比should稍重。 We ought to defend our country. 我們應(yīng)當(dāng)保衛(wèi)我們的國家。（每一個(gè)公民應(yīng)盡的義務(wù)） You ought to respect your parents. 你應(yīng)當(dāng)尊敬你的父母。 Oughtn't we to do everything possible to stop pollution 難道我們不應(yīng)當(dāng)盡可能地制止污染嗎？ 2表示推測，暗含很大的可能，可譯為“應(yīng)該是，會是”。 Prices ought to come down soon. 價(jià)格

41、可能會很快下跌。 Han Mei ought to know his telephone number. 韓梅該知道他的電話號碼。 There's a fine sunset; it ought to be a fine day tomorrow. 今天有晚霞，明天應(yīng)該是個(gè)好天。 3ought to和should一樣，表示對現(xiàn)在或以前應(yīng)做的事卻沒做的責(zé)怪、批評。 You ought to be washing your clothes. Why are you playing Ping-Pong 你應(yīng)該在洗衣服（可是你沒洗）。為什么你在打乒乓球？ You ought to have h

42、anded in the exercise last week. 你上周就應(yīng)當(dāng)交練習(xí)。（可你沒交，含責(zé)備的意思。） He ought to have asked me before he took my bike. 他在用我自行車之前應(yīng)該和我講一聲。 4ought to 與should的比較。 ought to 和should的含義較近，但不完全相同。ought to表示“應(yīng)該”， 是從“義務(wù)”或“按理推斷”的角度來講的。should則是從說話人的個(gè)人看法這一角度來講的。 You are her mother. You ought to look after her. 你是她的母親，你應(yīng)當(dāng)照管

43、她。（是道義上的責(zé)任，不能和should互換。） We should encourage him for we are his classmates. 我們應(yīng)該鼓勵他，我們是他的同班同學(xué)??！ 提示： 表示“義務(wù)”時(shí)，我們在口語中可以用had better或be supposed to 來代替should和ought to。 If you are not well, you had better ask Alice to go instead. 如果你不舒服，你最好叫艾麗絲代替你去。 I'm supposed to be there at 8 o'clock. 我應(yīng)該八點(diǎn)到那里。

44、Gused to 1used to表示過去的習(xí)慣或過去某時(shí)期的狀況，但現(xiàn)在已不存在。 He used to drink tea but now he drinks coffee. 他過去總是喝茶但現(xiàn)在他喝咖啡了。（強(qiáng)調(diào)現(xiàn)在不喝茶了） I know where there used to be a river here. 我知道這兒以前哪里有條河。（現(xiàn)在沒有河了） When I was a child I didn't use to like tomatoes. 我小時(shí)候不喜歡吃西紅柿。 He is not what he used to be. 他已不是原來的他了。 Where did

45、 you use to live before you came here 來此之前你住在什么地方？ 2would 和used to的用法區(qū)別。 used to表示過去與現(xiàn)在或過去某時(shí)與后來的情況有不同，強(qiáng)調(diào)“現(xiàn)已無此習(xí)慣了”，而would只表示過去的情況，與現(xiàn)在無關(guān)。 When he was young, he would smoke a lot. 他年輕時(shí)總是吸許多煙。（不含有和現(xiàn)在比較，現(xiàn)在他也許還在抽，也許不抽了。） He used to live in the country, but now he lives in the city. 他過去住在鄉(xiāng)下，現(xiàn)在住在城里。 used to

46、可表示過去的習(xí)慣動作或狀態(tài)，而would只表示過去的習(xí)慣動作。 Kate used to be very thin. 以前凱特非常瘦。 There used to be a building at the street corner, but it has been pulled down. 街道拐角處過去有座樓房，現(xiàn)在拆了。（不用would） used to可泛指過去的習(xí)慣動作或狀態(tài)，而would表示過去的習(xí)慣動作時(shí)，往往要帶有一個(gè)特定的時(shí)間狀語。 【誤】We would play hide-and-seek in the fields. 【正】We used to play hide-an

47、d-seek in the fields. 我們過去常在田野里玩捉迷藏。 【正】Whenever we were in the country, we would play hide-and-seek in the fields. 每當(dāng)我們在鄉(xiāng)下，我們都在田野里玩捉迷藏。Hdare dare既可用作情態(tài)動詞，也可用作行為動詞，指勇氣和膽量上的可能，可譯為“敢”。 1情態(tài)動詞dare dare作為情態(tài)動詞時(shí)主要用于疑問句和否定句，一般不用于肯定句中。 I dare not daren't walk through the forest at night. 我不敢在黑夜穿過森林。 - Da

48、re you walk through the forest at night 你敢在黑夜穿過森林嗎？ - Yes, I dare. 是的，我敢。 - No, I daren't. 不，我不敢。 He dare not drive too fast on the rainy day. 下雨天他不敢開得太快。 He dared not do it last year. 去年他不敢做這事。（dare的過去時(shí)為dared） 可以用于表示懷疑的名詞性從句中。 I wonder how he dare say such things. 我真奇怪他怎么竟敢說出這樣的話。 We don't

49、know whether he dare climb the mountain. 我們不知道他是否敢爬那座山。 可以用于條件狀語從句中。 If the enemy dare enter the village, we'll fight against them to the end. 如果敵人敢進(jìn)入村里，我們就和他們戰(zhàn)斗到底。 If you dare cheat in your exam, I will give you some punishment. 如果你們敢在考試中作弊，我就懲罰你們。2行為動詞dare dare可以作為行為動詞，多用于肯定句中，但也可用在疑問句和否定句中 He

50、 will dare any danger. 他敢面對任何危險(xiǎn)。 He dared me to jump over the stream. 他激我跳過小溪。 Did anyone dare to admit it 有人敢于承認(rèn)嗎？ I have never dared (to) go back to take a look. 我再也不敢返回去看一眼了。（否定句中to可省略） 和其他行為動詞一樣，dare在句子中要隨著主語的人稱和數(shù)發(fā)生變化。 He doesn't dare to walk at night. 他不敢走夜路。（作行為動詞） He daren't walk at n

51、ight. 他不敢走夜路。（作情態(tài)動詞） Does he dare to walk at night 他敢走夜路嗎？（作行為動詞） Dare he walk at night 他敢走夜路嗎？（作情態(tài)動詞） He didn't dare to walk at night fifteen years ago. 15年前他不敢走夜路。（作行為動詞） He daren't walk (=dared not walk) at night fifteen years ago. 15年前他不敢走夜路。（作情態(tài)動詞） Will you dare to do the same experimen

52、t tomorrow 明天你敢做同樣的實(shí)驗(yàn)嗎？（作行為動詞） Dare you do the same experiment tomorrow？ 明天你敢做同樣的實(shí)驗(yàn)嗎？ （作情態(tài)動詞）必背： 英語口語中dare的幾個(gè)常用結(jié)構(gòu)： I dare say. 我想, 大概, 可能, 或許 I dare say things will improve. 我想情況會好轉(zhuǎn)的。 How dare you . 你怎么敢？ How dare you ask me such a question 你怎么敢問我這樣的問題？ I dare you . 我諒你也不敢 I dare you to tell your pa

53、rents!我諒你也不敢告訴你父母！Ineed 1情態(tài)動詞need need 和dare一樣，作為情態(tài)動詞時(shí)，主要用于否定句和疑問句，一般不用于肯定句中（在肯定句中常被 must, have to, ought to, should等情態(tài)動詞取代）。作為情態(tài)動詞，它的詞形只有need一種形式。 You needn't return the book now. You can keep it till next week if you like.你現(xiàn)在不必還書， 如果愿意，你可以下周還。（needn't = don't have to） Need I hand in my

54、 homework now 我現(xiàn)在就要交家庭作業(yè)嗎？ - Need he finish the article next week他要下個(gè)星期完成這篇文章嗎？ - Yes, he must.是的，他必須完成。 - No, he needn't. 不，他不需要。（= he doesn't have to）2行為動詞need need和dare一樣，也可以作行為動詞，可用于肯定句、否定句和疑問句中。行為動詞need有人稱和數(shù)的變化。 Plant needs water. 植物需要水。 My shirt needs a button. 我的襯衫需要一枚鈕扣。 My car needs repairing. 我的車該修理了。 He has grown up. We don't need to worry about him. 他已經(jīng)長大了，我